OBD-II code · Chassis

C0090 Hydraulic Brake Pressure Sensor Circuit

The brake pressure sensor in the master cylinder or hydraulic block reports an implausible signal or no signal. The fault disables ABS, stability control and brake assist.

Is it safe to drive with C0090?

Usually safe for short trips, but don’t ignore it: the underlying fault can get more expensive over time.

Common causes

  • Most likelyPressure sensor element failed
  • PossibleSensor wiring fault

Symptoms

  • ABS warning light on
  • ESC/stability control deactivated
  • Possible reduced brake assist
  • Speedometer may behave erratically

Repair at a glance

Difficulty
Hard
DIY friendly
Best left to a mechanic
Typical labour
1–3.5 h
Emissions test
Usually unaffected
Parts involved
Brake Pressure Sensor, ABS Control Module, Sensor Wiring

Code data: OBDex open dataset (CC0). Labour times are typical ranges, not a quote.